Lock cylinder

ABSTRACT

A lock cylinder having an emergency function and including a housing containing a key-removable core supporting a rotatable key plug for driving a roll-back supported on the housing externally thereof. An axially movable control member received in the housing rearwardly of the key plug cooperates in one position with a stop lug associated with the housing to limit angular movement of the key plug and the roll-back in one and an opposite direction when an operating key is employed to operate the lock cylinder. An elongated emergency key is provided which extends through the key plug to engage and shift the control member to another position out of alignment with the stop lug to effect free rotation of the key plug and the roll-back in one and an opposite direction. The effective length of the emergency key is critical.

[ 1 Jan. 30, 1973 [54] LOCK CYLINDER [75] lnventor: Walter E. Surko, Jr., Southington,

' Conn.

[73] Assignee: Emhart Corporation, Bloomfield,

Conn.

[22] Filed: June 28,1971

211 Appl. No.: 157,264

Primary Examiner-Marvin A. Champion Assistant ExaminerRobert A. Hafer Attorney-Rober B. McCormick et al.

[57] ABSTRACT A lock cylinder having an emergency function and including a housing containing a key-removable core supporting a rotatable key plug for driving a roll-back supported on the-housing externally thereof. An axially movable control member received in the housing rearwardly of the key plug cooperates in one position tg zgggg with a stop lug associated with the housing to limit angular movement of the key plug and the roll-back in [58] Field of Search one and an opposite direction when an operating key 70/369 is employed to operate the lock cylinder. An elongated emergency key is provided which extends [56] References through the key plug to engage and shift the control member to another position out of alignment with the V UNITED STATES PATENTS stop lug to effect free rotation of the key plug and the 2,070,233 2/1937 Liss ..70/364 R ro l-back in one and an opposite direction. The effecl,2l6,859 2/1917 Shaw ..70/379 A tive length of the emergency key is critical. 3,605,463 9/1971 Epstein ..70/364 A o 2,064,955 l2/l936 Singer et al ..70/364 A 11 Clam", 5 Drawmg Flgul'es FOREIGN PATENTS OR APPLICATIONS 872,276 77135?"ma nifier.....;.1 ..70 379 it IO 4 p 50 5 4 '8 l 1 4O v l 11 Q" 1 ,72 Li-11w I W 60/ 4 2.5 I \J46 'PATENTEDJM 30 I975 INVENTOR. WALTER E. 'SURKO Jr ATTORNEYS LOCK CYLINDER BACKGROUND OF THE INVENTION This invention relates in general to locks and deals more particularly with a key-operated pin tumbler lock cylinder. The lock cylinder of the present invention is particularly adapted for use with a lock mechanism embodying multiple locking functions, as for example, a lock mechanism including both a latch bolt and a dead bolt. Such a lock mechanism is particularly suitable for use on the door of a hotel room or the like where it is desirable that the latch bolt be operable by a plurality of keys of differing class and the dead bolt be protracticlass of key superior to all other classes for retracting all of the bolts of an associated lock mechanism.

SUMMARY OF THE INVENTION In accordance with the present invention an improved lock cylinder is provided which includes a rotatable key plug, an external roll-back driven by the key plug and a movable control member contained within the lock cylinder and operable in one position to limit angular movement of the key plug and the rollback in response to operation of any one of a plurality of keys of differing class. An emergency key, superior to the keys of all other classes, is employed to move the control member to another position wherein the key plug and roll-back are freely rotable in one and an opposite direction in response to operation of the emergency k y BRIEF DESCRIPTION OF THE DRAWING I FIG. 1 is a side elevational view of a lock cylinder embodying the present invention and having a keyremovable core shown with an operating key therein, the housing and roll-back being shown in vertical section. FIG. 2 is a rear elevational view of the lock cylinder of FIG. 1.

FIG, 3 is a front elevational view of the lock cylinder of FIG. 1 shown with the core removed therefrom.

FIG. 4 is a sectional view taken along the line 4-.-4 of FIG. 1.

FIG. 5 is generally similar to FIG. 1 but shows the lock cylinder with an emergency key therein.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT The present invention is illustrated and described with reference to a lock cylinder of key-removable core type, however, it should be understood that the invention is not limited to lock cylinders of this type. Referring now to the drawing, a lock cylinder embodying the present invention and indicated generally by the reference numeral comprises a cylindrical housing or shell 12 which has a conventional roll-back or cam 14 supported externally thereof for rotation relative thereto. A key-removable core 16 locked in the hous-.

ing supports a rotable key plug 18 for driving the rollback 14. All of the aforesaid parts may be and preferably are of substantially standard construction. In accordance with the present invention, a control mechanism disposed within the housing 12 and indicated generally by the reference numeral 20 is operable-to control angular movement of the key plug 18 and the roll-back 14. More specifically, the control mechanism 20 includes a movable control member 22 biased to one position shown in FIG. 1 wherein it is aligned and engageable with a fixed stop lug 24' on the housing to limit angular movement of the key plug and the roll-back in response to manual manipulation of an operating key 25. An emergency key 26, superior to all other keys associated with the lock cylinder, moves the control member 22 to and retains it in another position out of alignment with the stop lug 24, as shown in FIG. 5. When the control member 22 is in the latter position, the key plug 18 and the roll-back 14 are freely rotable in one and an opposite direction in response to rotation of the key 26.

Considering the lock cylinder 10 in further detail, the cylindrical housing 12 has a rear wall 27 and is externally threaded for connection with an, associated lock mechanism (not shown). A flange 28, at the forward end of the housing is adapted to engage the outer face of a door (not shown) or an escutcheon plate secured thereto. The housing 12 also includes a recess or core receptacle 30 which has a figure-8 shaped cross section formed by parallel intersecting parti-cylindrical upper and lower bores 32 and 34 which open through the outer end thereof. The lower bore 34 extends into the rear wall 27 for some distance beyond the upper bore 32. Another forwardly opening parti-cylindrical bore 36 coaxially aligned with the upper bore. 32, but of somewhat smaller diameter, is formed in the rear wall 27 and intersects the lower bore 34. A generally cylindrical bore 38 of somewhat smaller diameter than the lower bore 34'and coaxially aligned therewith extends through the rear wall 27 to provide a journal for a generally cylindrical cam driver 40. An integral annular flange 4 2.on the inner end of the cam driver 40 bears against the forwardly facing surface of the rear wall 27.

The cam 14 is received on a reduced cylindrical rear ment 52 arranged for limited angular movement relative to the body 50 and with the key plug to lock the core 16 in or release it form the housing 12 when the key plug is operated by a control key (not shown).

More specifically, the body 50 includes a recess 54 for containing the locking element 52. The locking element has a locking shoulder 53 thereon and is arranged for limited angular movement with the key plug 18 and the figure-8 shaped profile of the body 50. In the locking position, the locking shoulder 53 is at least partially disposed within a recess 55 in the housing to releasably retain the lock core 16 in assembly with the housing.

The key plug 18 is of a generally conventional, type and has a cylindrical body with a paracentric fluted keyway 56 formed therein which extends axially therethrough. A pair of cylindrical holes 58, 58 extend axially into the key plug on opposite sides of the keyway 56 and open through the rear face of the key plug to receive the drive pins 48, 48. A generally U- shaped retaining washer 60 received in an annular recess at the rear end of the key plug 38 cooperates with an annular shoulder formed at the forward end of the plug to retain the plug in assembly with the body 50.

The key plug 18 and the locking element 52 are locked against rotation by conventional stacks of pin tumblers indicated at 62, 62 and received in a plurality of pin tumbler holes formed inthe body 50, the locking element 52 and the key plug 18. A control line of shear is formed between the locking element 52 and the body 50. An operating line of shear is formed between the locking element 52 and the key plug.l8. When a control key (not shown) is inserted in the key plug 18, the pin tumblers 62, 62 are aligned with the control line of shear so that the locking element 52 may be moved through a limited angle with the key plug 18 and relative to the body 50 to a position wherein the locking shoulder 53 is disposed within the locking recess 55 in the housing 12. When the control key is in its shed posi-' tion, the core 16 is locked within the housing 12. Thereafter when the operating key 24 or another key of higher order is inserted in the key plug 18, the pin tumblers 62, 62 move into alignment with the operating line of shear so that the key plug 18 may be rotated, key rotation being limited only by the control mechanism 20. For a more complete disclosure of a lock core of the aforedescribed type, reference may be had to eopending application Ser. No. 10,190 of Surko et al. for Lock Core} filed Feb. 10, 1970, and assigned to the assignee of the. present application.

Further considering the control mechanism 20, the stop lug 24 is received in the bore 36 and comprises a generally circular disc which has a diameter substantially equal to the diameter of the parti-cylindrical bore 36. A forwardly projecting central portion of the stop lug bears against the rear surface of the body 50 when the core 16 is locked in the housing 12. The stop lug is preferably staked into assembly with the housing as indicated at 64, 64 in FIG. 3 so that it remains in assembly therewith when the core 16 is removed. The central member 22 is a generally cylindrical disc which has a radially outwardly extending projection 66, as best shown in FIG. 3, and a pair of diametrically spaced notches 68, 68 for slidably receiving the drive pins 48, 48. An' annular spring washer 70 staked to the rear surface of the control member as indicated at 72 has a marginal portion thereof disposed rearwardly of the stop lug 24 and cooperates therewith to retain the control member 22 in assembly with the cam driver 40. The spring washer 70 biases the control member toward the rear surface of the key plug 18 or toward a first position wherein it engages the rear surface of the key plug. When the control member 22 is in its first position, it is generally aligned with the stop lug 24 so that the projection 66 is engageable with the stop lug to limit rotation of the cam 14 and the key plug 18, as shown in FIG. 3, the limits of rotation being indicated by broken line positions of the control member 22.

The elongated emergency key 26 is adapted to extend through and beyond the key plug 18 to engage the control member proximate its center and bias it rearwardly to a second position out of alignment with the stop lug 24, as shown in FIG. 4. The cam driver arrests the rearward movement of the control member 22 when the control member attains its second position. When the control member 22 is in its second position the key plug 18 and the cam 14 may be freely rotated in one and an opposite direction in response to manual manipulation of the emergency key 26.

The lock cylinder 10 is so constructed and arranged that the length of the emergency key 26 is quite critical. Thus if an attempt is made to use a properly bitted key of excessive length in place of a proper emergency key, the control member will attain its second position before the key bits are properly aligned with the pin tumblers 62, 62. Thus, the lock cylinder cannot be operated. If an attempt is made to use a properly bitted key of insufficient length as an emergency key, the control member will not be biased to a position out of alignment with the stop lug 24 to free the key plug and cam for unlimited rotation. It will now be apparent that the key plug, the control member and the roll-back will be freely rotable in one and an opposite direction only when the control member is in its second position.

I claim:

1. A look cylinder comprising a housing having a recess therein, a key plug supported in said recess for rotation relative to said housing and having a keyway therein, a roll-back supported externally of said housing for rotation relative thereto, drive means for connecting said roll-back to said key plug for rotation therewith, a stop lug in said housing rearwith of said key plug, a control member in said housing rearward of said key plug and rotable with said key plug and said roll-back, said control member being movable relative to said key plug and said housing between a first position wherein said control member is in general alignment with said stop lug and a second position out of alignment therewith, means for biasing said control member toward said key plug and to said first position, said control member in said first position being engagable with said stop member to limit angular movement of said key plug and said roll-back in one and an opposite direction, said key plug said control member and said roll-back being freely rotable in one and an opposite direction when said control member is in said second position, an operating key .insertable in said keyway for rotating said key plug with said control member in said first position, and an emergency key insertable in said keyway and engagable with said control member to bias said control member to and retain said control member in said second position and for rotating said key plug with said control member in said second position.

2. A lock cylinder as set forth in claim 1 wherein said control member is axially movable relative to said key plug and in general radial alignment therewith in said first position.

3. A lock cylinder as set forth in claim 1 including means for arresting further movement of said control member when said control member attains said second position, said control member, said key plug and said roll-back being freely rotable in said one and said opposite direction only when said control member is in said second position. i

4. A lock cylinder as set forth in claim 1 including a removable core slidably receivedin said recess and adapted for releasable locking engagement with said housing, said key plug comprising a part of said core, and a change key insertablein said keyway for rotating said key plug in one and an opposite direction respectively to lock said core in said housing and to release said core therefrom.

5. A lock cylinder as set forth in claim 4 wherein said control member is axially movable relative to said key plug and in general radial alignment therewith in said first position.

6. A lock core as set forth in claim 4 wherein said recess has a generally figure-8 cross sectional configuration and said core has a generally figure-8 cross sectional configuration complementing the cross sectional configuration of said recess.

7. A lock core as set forth in claim 4 wherein said recess is defined by a pair of parallel intersecting particylindrical bores, said stop lug is received in one of said bores and said control member is received in the other of said bores.

8. A lock core as set forth in claim 4 wherein said biasing means cooperates with said stop lug to retain said control member in assembled relation with said housing when said core is removed therefrom.

9. A lock core as set forth in claim 1 wherein said biasing means comprises a spring washer connected to said control member for rotation therewith.

10. A lock cylinder as set forth in claim 1 wherein said drive means comprises a drive member joumaled on said housing for coaxial rotation with said key plug and having a pair of axially parallel drive pins extending into said recess and said key plug has a pair of axially extending openings therein respectively receiving said drive pins, said control member supported for axial movement on said pins and relative to said drive member and for rotation with said drive member.

11. A lock cylinder as set forth in claim 1 wherein said control member is supported for axial movement by said drive means. 

1. A lock cylinder comprising a housing having a recess therein, a key plug supported in said recess for rotation relative to said housing and having a keyway therein, a roll-back supported externally of said housing for rotation relative thereto, drive means for connecting said roll-back to said key plug for rotation therewith, a stop lug in said housing rearwith of said key plug, a control member in said housing rearward of said key plug and rotable with said key plug and said roll-back, said control member being movable relative to said key plug and said housing between a first position wherein said control member is in general alignment with said stop lug and a second position out of alignment therewith, means for biasing said control member toward said key plug and to said first position, said control member in said first position being engagable with said stop member to limit angular movement of said key plug and said roll-back in one and an opposite direction, said key plug said control member and said roll-back being freely rotable in one and an opposite direction when said control member is in said second position, an operating key insertable in said keyway for rotating said key plug with said control member in said first position, and an emergency key insertable in said keyway and engagable with said control member to bias said control member to and retain said control member in said second position and for rotating said key plug with said control member in said second position.
 1. A lock cylinder comprising a housing having a recess therein, a key plug supported in said recess for rotation relative to said housing and having a keyway therein, a roll-back supported externally of said housing for rotation relative thereto, drive means for connecting said roll-back to said key plug for rotation therewith, a stop lug in said housing rearwith of said key plug, a control member in said housing rearward of said key plug and rotable with said key plug and said roll-back, said control member being movable relative to said key plug and said housing between a first position wherein said control member is in general alignment with said stop lug and a second position out of alignment therewith, means for biasing said control member toward said key plug and to said first position, said control member in said first position being engagable with said stop member to limit angular movement of said key plug and said roll-back in one and an opposite direction, said key plug said control member and said roll-back being freely rotable in one and an opposite direction when said control member is in said second position, an operating key insertable in said keyway for rotating said key plug with said control member in said first position, and an emergency key insertable in said keyway and engagable with said control member to bias said control member to and retain said control member in said second position and for rotating said key plug with said control member in said second position.
 2. A lock cylinder as set forth in claim 1 wherein said control member is axially movable relative to said key plug and in general radial alignment therewith in said first position.
 3. A lock cylinder as set forth in claim 1 including means for arresting further movement of said control member when said control member attains said second position, said control member, said key plug and said roll-back being freely rotable in said one and said opposite direction only when said control member is in said second position.
 4. A lock cylinder as set forth in claim 1 including a removable core slidably received in said recess and adapted for releasable locking engagement with said housing, said key plug comprising a part of said core, and a change key insertable in said keyway for rotating said key plug in one and an opposite direction respectively to lock said core in said housing and to release said core therefrom.
 5. A lock cylinder as set forth in claim 4 wherein said control member is axially movable relative to said key plug and in general radial alignment therewith in said first position.
 6. A lock core as set forth in claim 4 wherein said recess has a generally figure-8 cross sectional configuration and said core has a generally figure-8 cross sectional configuration complementing the cross sectional configuration of said recess.
 7. A lock core as set forth in claim 4 wherein said recess is defined by a pair of parallel intersecting particylindrical bores, said stop lug is received in one of said bores and said control member is recEived in the other of said bores.
 8. A lock core as set forth in claim 4 wherein said biasing means cooperates with said stop lug to retain said control member in assembled relation with said housing when said core is removed therefrom.
 9. A lock core as set forth in claim 1 wherein said biasing means comprises a spring washer connected to said control member for rotation therewith.
 10. A lock cylinder as set forth in claim 1 wherein said drive means comprises a drive member journaled on said housing for coaxial rotation with said key plug and having a pair of axially parallel drive pins extending into said recess and said key plug has a pair of axially extending openings therein respectively receiving said drive pins, said control member supported for axial movement on said pins and relative to said drive member and for rotation with said drive member. 